Tire pressure monitoring system for motorcycles

ABSTRACT

A tire pressure monitoring system for a motorcycle includes a tire valve stem mounted tire pressure gauge and an externally powerable remote display unit. The pressure gauge includes a pressure sensor, a wake circuit, a processor, and a first radio frequency (RF) module. The remote display unit includes a second RF module and a display. The wake circuit is adapted to activate the processor periodically at a predetermined interval of time and causes the processor to receive an output signal from the pressure sensor. The output of the pressure sensor is indicative of a tire pressure detected by the pressure sensor. The remote display unit is adapted to display the measured tire pressure value without any user input.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/256,789, filed Oct. 30, 2009, and entitled “TIREPRESSURE MONITORING SYSTEM FOR MOTORCYLCES,” which application is herebyincorporated by reference in its entirety.

FIELD OF INVENTION

The present invention relates to tire pressure measurement and tirepressure gauges.

BACKGROUND

Pressure gauges are conventionally used for measuring the pressure of agas or a liquid, such as an air pressure. Tire pressure gauges, as anexample, measure the inflation pressures of vehicle tires, suchinformation being useful for maintaining optimal tire performance andavoiding unnecessary wear. Conventional tire pressure gauges are held inthe hand, and require the user to locate a tire valve, unscrew a capfrom the valve, and engage the tire pressure gauge with the valve. Atnight, it is difficult to locate the valve. Tire valve caps are usuallycovered in a film of dirt, which comes off on the user's fingers whenremoving and replacing the cap. While some vehicles have systems formonitoring of tire pressure using tire pressure gauges withradiofrequency transmitters installed in the tires, and systems forinterrogating the gauges and receiving readings installed in thevehicle, such systems are not practical to install on existing tires andvehicles. Furthermore, such systems require user activation to measureand display or indicate the tire pressures. Alternative tire pressuremeasurement systems are, therefore, desirable.

SUMMARY OF THE INVENTION

A tire pressure monitoring system includes a tire valve-stem mountedtire pressure gauge and an externally powerable remote display unit. Thepressure gauge includes a pressure sensor, a wake circuit, a processor,and a first radio frequency (RF) module. The remote display unitincludes a second RF module and a display. The wake circuit is adaptedto activate the processor periodically and to cause the processor toreceive periodically an output signal from the pressure sensorindicative of a measured tire pressure. The remote display unit isadapted to display a value indicative of the tire pressure valuemeasured by the pressure sensor without any user input. The tirepressure gauge and the remote display unit are adapted to be in wirelesscommunication with each other via the first and second RF modules. Theremote display unit may be powered through an AC adaptor.

In an embodiment of the invention, responsive to an activation signalfrom the wake circuit, the processor receives an output signal from thepressure sensor indicative of the measured tire pressure. The processorthen compares the measured tire pressure value with the immediatelypreviously measured tire pressure value stored in the memory. If therecently measured tire pressure value differs from the value stored inthe memory by an amount more than a predetermined value, the processorcauses the first RF module to transmit a wireless signal indicative ofthe recently measured tire pressure value. The wireless signal isreceived by the remote display unit via the second RF module. The remotedisplay unit is adapted to display the most recent measured tirepressure value transmitted by the tire pressure gauge.

According to an embodiment of the invention, a tire pressure monitoringkit for a motorcycle includes a first and a second tire pressure gauge.Each of the tire pressures is configured to be mounted on a valve stemof a tire of the motorcycle and includes a pressure sensor, a processor,a wake circuit and a radio frequency module. The wake circuit isconfigured to activate the processor to receive an output of thepressure sensor periodically at a predetermined interval of time. Theoutput is indicative of a tire pressure detected by the pressure sensor.The kit further includes a remote display unit including a second radiofrequency module, a memory and a display. The second module isconfigured to wirelessly communicate with the radio frequency modules ofthe first and second tire pressure gauges.

According to embodiment of the invention, a method for monitoring tirepressure for a motorcycle includes the steps of mounting a tire pressuregauge on a valve stem of a tire of a motorcycle. A processor in the tirepressure gauge is periodically activated to receive an input from apressure sensor in the tire pressure gauge, which input is indicative ofa tire pressure detected by the pressure sensor. The processor causes aradio frequency module in the tire pressure gauge to emit a wirelesssignal which signal is indicative of a tire pressure detected by thepressure sensor. The wireless signal emitted by the radio frequencymodule is received at an externally powerable remote display unit. Agraphical indictor representative of a value of the tire pressuredetected by the pressure sensor is displayed in the remote display unit.

BRIEF DESCRIPTION OF THE DRAWINGS

Understanding of the present invention will be facilitated byconsideration of the following detailed description of the exemplaryembodiments of the present invention taken in conjunction with theaccompanying drawings, in which like numerals refer to like parts and inwhich:

FIG. 1 is an isometric view of a tire pressure gauge, according to anembodiment of the present invention;

FIG. 2 is a cross-sectional view, along line 2-2 of FIG. 1, of the tirepressure gauge of FIG. 1;

FIG. 3 is a block diagram of components of the tire pressure gauge ofFIG. 1;

FIG. 4A is an exploded view of a tire pressure gauge in accordance withan alternative embodiment of the invention;

FIG. 4B is a view of the tire pressure gauge of FIG. 4A, as assembled;

FIG. 5 is a block diagram of components in a tire pressure gauge inaccordance with the embodiment of FIG. 4A together with an RF source;

FIG. 6 is an exploded view of a tire pressure gauge in accordance withan alternative embodiment of the invention;

FIG. 7 is an exploded view of a tire pressure gauge in accordance withanother alternative embodiment of the invention;

FIG. 8 is a view of an alternative embodiment of a tire pressure gaugeouter housing;

FIG. 9 is a view of an alternative embodiment of a pressure module inaccordance with an embodiment of the invention;

FIG. 10 is a block diagram of an alternative embodiment of a tirepressure gauge;

FIG. 11 is a cross-sectional view of a tire pressure gauge, according toyet another embodiment of the invention;

FIG. 12 is an exploded view of the tire pressure gauge of FIG. 11;

FIG. 13 is a block diagram of a remote control unit according to anembodiment of the invention;

FIG. 14 is a remote display unit of a tire pressure monitoring system,according to an embodiment of the invention;

FIG. 15 is an exploded view of the remote display unit of FIG. 14;

FIG. 16 is a schematic diagram of a tire pressure monitoring system,according to an embodiment of the invention;

FIG. 17A is a layout of the LCD display of the remote display unit ofFIG. 14, according to an embodiment of the invention;

FIG. 17B is an exemplary view of LCD display of the remote control unitof

FIG. 17A showing exemplary values, according to an embodiment of theinvention;

FIGS. 18A and 18B illustrate a process flow for preparing a system ofFIG. 16 for use, according to an embodiment of the invention;

FIG. 19 is a process flow for registration of valve cap mounted tirepressure gauges with a remote display unit, according to an embodimentof the invention;

FIG. 20 is a layout of the LCD display of the remote display unit ofFIG. 14, according to another embodiment of the invention;

FIG. 21 is a layout of the LCD display of the remote display unit ofFIG. 14, according to yet another embodiment of the invention;

FIG. 22 is a schematic representation of a tire pressure monitoringsystem, according to an embodiment of the invention; and

FIG. 23 is a process flow diagram of a process of transmitting awireless signal indicative of a tire pressure detected by a pressuresensor, according to an embodiment of the invention.

DETAILED DESCRIPTION

It is to be understood that the figures and descriptions of the presentinvention have been simplified to illustrate elements that are relevantfor a clear understanding of the present invention, while eliminating,for purposes of clarity, many other elements found in typical tirepressure gauges and tire pressure measurement systems. However, becausesuch elements are well known in the art, and because they do notfacilitate a better understanding of the present invention, a discussionof such elements is not provided herein. The disclosure herein isdirected to all such variations and modifications known to those skilledin the art.

Further, it should be understood that the several views of the housings,displays and general configurations shown in the figures include manydecorative or ornamental features, aspects of which the particulars maybe changed while maintaining the device's utility and without departingfrom the scope and spirit of the present invention.

Referring to FIG. 1, tire pressure gauge 10 has a wall 20, whichincludes cylindrical sidewall 22 and planar top wall 24, as well as aplanar bottom wall, not shown in FIG. 1. Wall 20 defines an interiorchamber, described below. Port 30 in wall 20 is provided, and includes apassage which communicates with and opens into the interior chamber,which passage may be closed by a valve (not shown in FIG. 1), such as ableeder or pin valve. Port 30 is adapted to be attached to a nozzle of aconventional air hose, and has a threaded cylindrical outer surface 32adapted to mate with a correspondingly threaded boss in a nozzle of suchan air hose. Port 30 has a central rod or needle or pin 34 which, whenengaged, such as by a central pin in a nozzle of an air hose, opens ableeder or pin valve associated with port 30.

Referring now to FIG. 2, there is shown a cross-sectional view, alongline 2-2, of the tire pressure gauge 10 of FIG. 1. Chamber 21 definedwithin wall 20 can be seen. Chamber 21 has openings only at port 30 andport 40, and is otherwise sealed. At port 30, a valve is provided toselectively seal port 30. Port 40 is adapted to engage with and open theneedle valve on a suitable tire valve stem. Port 40 is preferablyadapted to engage with and open the needle valve on a conventional tirevalve stem, so that the conventional tire valve stem requires nomodification for installation of a device in accordance with anembodiment of the invention. A tire valve stem is typically in the formof a tube, threaded on the exterior near the end thereof, to permitattachment of a protective cap, and having a valve, referred tovariously as a pin valve, bleeder valve, or Schrader valve. This type ofvalve is kept normally closed by a combination of air pressure and aspring urging a stopper into contact with an opening. A pin extendingout of the valve may be urged inward, such as by a piston in a nozzle ofa service station air hose, to open the valve to permit the introductionof pressurized air into the tire.

Port 40 has a threaded boss 42 adapted to sealingly engage with athreaded tire valve stem. Pin 44 within boss 42 is adapted to open aneedle valve on a valve stem when port 40 is in engagement with asuitable valve stem. PCB 60 is interior to chamber 21 and has thereondevices indicated generally at 61, 62. Port 30 has a pin valve 34including a stopper 36 that is normally closed by pressure withinchamber 21, or may be spring loaded. Pin 34 is coupled to stopper 36 sothat urging of pin 34 toward chamber 21 causes stopper 36 to disengageand permit air to move between chamber 21 and the interior of port 30.Thus, with gauge 10 affixed to a valve stem of a tire, the tire may bepressurized by engaging the nozzle of a service station air hose withport 30.

As set forth above, gauge 10 includes a pressure sensor located withinwall 20 defining chamber 21. Referring now also to FIG. 3, there isshown a block diagram of an arrangement 300 suitable for use withinchamber 21 of FIGS. 1 and 2. An exemplary arrangement 300 generallyincludes a processor 310, a memory 320 accessible to processor 310,optional analog to digital converter 330, pressure sensor 340, a radiofrequency (RF) module or antenna 350, a wake circuit 360, and anoptional motion sensor 370.

“Processor”, as used herein, generally refers to a circuit arrangementthat may be contained on one or more silicon chips, and/or integratedcircuit (IC) boards, and that contains a Central Processing Unit (CPU).The CPU may generally include an arithmetic logic unit (ALU), whichperforms arithmetic and logical operations, and a control unit, whichextracts instructions from memory and decodes and executes them, callingon the ALU when necessary.

Processor 310 may take the form of a microprocessor, and may be a lowpower CMOS processor with an embedded analog to digital converter, byway of non-limiting example only. The present invention is operable withcomputer storage products or computer readable media that containprogram code for performing the various computer-implemented operations.The computer-readable medium is any data storage device that can storedata which can thereafter be read by a computer system such as amicroprocessor. The media and program code may be those speciallydesigned and constructed for the purposes of the present invention, orthey may be of the kind well known to those of ordinary skill in thecomputer software arts. Examples of computer-readable media include, butare not limited to magnetic media such as hard disks, floppy disks, andmagnetic tape; optical media such as CD-ROM disks; magneto-opticalmedia; and specially configured hardware devices such asapplication-specific integrated circuits (ASICs), programmable logicdevices (PLDs), and ROM and RAM devices. Examples of program codeinclude both machine code, as produced, for example, by a compiler, orfiles containing higher-level code that may be executed using aninterpreter.

Processor 310 may include multiple inputs and outputs. In the exemplaryconfiguration illustrated in FIG. 3, processor 310 has an input coupledto wake circuit 360. Processor 310 may also be coupled to memory 320 toallow it to access its data contents. Processor 310 may have an inputcoupled to pressure sensor 340 optionally via analog-to-digitalconverter (A/D) 330. For example, where pressure sensor 340 provides ananalog output signal indicative of a pressure sensed using port 30, A/Dconverter 330 may communicate a digital signal indicative of the analogsignal output from pressure sensor 340 to processor 310. Where pressuresensor 340 provides a digital signal directly, A/D converter 330 mayoptionally be omitted. Also, where processor 310 is adapted to receiveanalog signals output from pressure sensor 340 directly, A/D converter330 may optionally be omitted. A/D converter 330 may be selected basedupon size limitations of chamber 21, an expected output from pressuresensor 340, accepted input for processor 310 and available power sources(not shown) for pressure gauge 10 (such as one or more batteriescontained within chamber 21), for example.

Memory 320 may be internal or external to processor 310 and may take theform of one or more random-access memory (RAM), read-only memory (ROM),programmable read-only memory (PROM), erasable programmable read-onlymemory (EPROM), or electrically erasable programmable read-only memory(EEPROM) chips, by way of non-limiting example only.

Pressure sensor 340 may be any one of a number of conventional sensorsfor detecting fluid pressure, and particularly air pressure, andselected to provide acceptable response over a range of pressuresanticipated in a particular application. By way of example, pressuresensor 340 may incorporate a MEMS based pressure die.

RF module or antenna 350 is in communication with processor 310 and isadapted to receive and transmit RF signals and includes electricalcircuit elements for receiving and transmitting RF signals, responsiveto activation signals from processor 310.

FIG. 4A is an exploded view of a tire pressure gauge 410, according toanother embodiment of the invention, and FIG. 4B is a view of tirepressure gauge 410 when assembled. Tire pressure gauge 410 has a singleport for receiving pressurized air from a tire valve stem, but does nothave an additional port for receiving pressurized air. Tire pressuregauge 410 may include a device for receiving power wirelessly. By way ofexample, tire pressure gauge 410 may include one or more radio frequencyantennas, such as those used in radiofrequency identification tags(RFIDs). When interrogated by a source of RF radiation at the properfrequency, such an antenna generates a current which may be usedvariously, directly by a processor and display for power, or to abattery or capacitor for storage and discharge of current to power aprocessor and display. A user may have a handheld or a remote unit thatserves as a source of RF radiation at the proper frequency.

Outer housing 470 may be substantially cylindrical, and have two pieces,namely a body portion 471 open at both ends and a cap 472 that closes adistal opening of body portion 471.

Inner housing 420 defines a chamber having an opening, when the tiregauge is fully assembled, only at port 440, and is otherwise sealed.Port 440 is adapted to engage with and open the needle valve on asuitable tire valve stem. Port 440 has a threaded boss 442 adapted tosealingly engage with a threaded tire valve stem. Piston 444 within boss442 is adapted to open a needle valve on a valve stem when port 440 isin sealing engagement with a suitable valve stem. PCBs 461, 462 aremounted exterior to the chamber and within outer housing 470, and maycarry thereon devices such as an RF antenna, battery, capacitor,processor, and wake up circuit. A pressure sensing die 480 is positionedat an end of the chamber and bolt 483, and seals the correspondingopening in inner housing 420.

Referring now to FIG. 5, a block diagram of tire gauge 410, in a systemtogether with a remote RF source/receiver 500, is illustrated. Tiregauge 410 may include a processor 510, an RF antenna 540, a power source560, such as a battery, a wake circuit 520, a pressure sensor 480, amemory 570, and an optional motion sensor 580. In use, the user placesthe handheld or remote RF source/receiver 500 in proximity to gauge 410,according to an embodiment of the invention. The distance betweenhandheld or remote RF source/receiver and tire pressure gauge 410 atwhich pressure gauge 410 will operate may be, in some embodiments, atleast about three to four feet, so that a user may stand next to thevehicle, holding the handheld or remote RF source/receiver 500 in thehand, and activate gauge 410 by activating handheld or remote RFsource/receiver 500, without the need to stoop or lean to bring handheldor remote RF source/receiver closer than three or four feet frompressure gauge 410. The distance may be greater in some embodiments, byway of example, sufficiently long that an activating device may belocated in a dashboard of the vehicle or mounted on a wall in thegarage. When RF radiation from remote RF source/receiver 500 is receivedby RF antenna 540, a current is produced by RF antenna 540. The currentmay be provided directly to processor 510, or to a capacitor 550 whichthen supplies a current to processor 510, or to battery 560, which thensupplies a current to processor 510. It will be understood that asuitable voltage is also furnished to pressure sensor 480, and optionalA/D converted 530.

Memory 570 may be internal or external to processor 510 and may take theform of one or more random-access memory (RAM), read-only memory (ROM),programmable read-only memory (PROM), erasable programmable read-onlymemory (EPROM), or electrically erasable programmable read-only memory(EEPROM) chips, by way of non-limiting example only.

In an exemplary embodiment, wake circuit 520 is adapted to activateprocessor 510, which, in turn, causes pressure sensor 480 to measure thetire pressure. In this configuration, a user is not required to activateremote RF source/receiver 500; rather, wake circuit 520 periodicallyactivates processor 510 after a predetermined interval of time,independent of any received signal or any motion detected by motionsensor 580. By way of non-limiting example only, wake circuit 520 may beadapted to activate processor 510 every thirty (30) seconds to causepressure sensor 480 to measure the tire pressure. It will be appreciatedthat the predetermined interval of time may be adjusted to be more thanor less than thirty (30) seconds. In an exemplary embodiment, eachmeasurement includes measuring the tire pressure three (3) times. Inother embodiments, each measurement may include measuring the tirepressure for more than or less than three (3) times. Processor 510causes a transmission of RF signal indicative of the measured tirepressure value via RF antenna 540, which RF signal may be received byremote RF source/receiver 500. In one configuration, wake circuit 520 isadapted to activate processor 510 when battery 560 is first installed inpressure gauge 410 by a user. Wake circuit 520 continues to periodicallyactivate processor 510 after a predetermined interval of time so long asbattery 560 provides sufficient power to wake circuit 520 and othercomponents of pressure gauge 410. Additionally, wake circuit 560 mayalso be configured to activate processor 510, responsive to a wirelesssignal received from a remote command device 500 (of FIG. 5). In anexemplary embodiment, motion sensor 370 is adapted to provide an outputsignal, responsive to detection of motion, which signal, upon receipt byprocessor 510, causes processor 510 to become activated.

In an exemplary configuration, battery power may be conserved byregulating the number of times and the conditions under which pressuregauge 410 transmits the measured tire pressure to remote RFsource/receiver 500. By way of non-limiting example, after everymeasurement, processor 510 compares the measured pressure with the valueof the previous measured pressure stored in memory 570. Tire pressuregauge 410 may transmit the value of the measured pressure only if themost recent measured tire pressure value differs from the previouslymeasured tire pressure by a predetermined value. In an exemplaryembodiment, pressure gauge 410 may transmit the value of the recentlymeasured pressure only if the most recent measured tire pressure valuediffers from the previously measured tire pressured by one (1) pound persquare inch (psi). Thus, power is expended to transmit a wireless signalonly if the most recent measured tire pressure value differs from thepreviously measured tire pressure by a predetermined value. After thecomparison and/or the transmission, processor 510 and the associatedcircuitry “sleeps” for a predetermined period of time before beingactivated again by wake circuit 520.

Referring now to FIG. 6, tire pressure gauge 610 is depicted in anexploded view. Tire pressure gauge 610 has as a power source battery 655adapted to be removed and replaced easily. In particular, tire pressuregauge 610 includes a battery compartment 656 having a lid 657 which maybe removed and replaced readily, and particularly by rotating. Lid 657is generally a solid cylinder, and has a latch at 657 a, which mateswith a protrusion at 656 a. By placing a flat object, such as a coin orscrewdriver blade, into slot 659 in lid 657, the user may turn lid 657sufficiently to disengage latch 657 a from protrusion 656 a, and therebyremove lid 657 and remove and replace battery 655. O-ring 658 may beprovided to prevent moisture from entering the interior of batterycompartment 656. Outer housing 670 may be substantially cylindrical, andhave two pieces, namely a body portion 671 open at both ends and batterycompartment 656 that closes a distal opening of body portion 671.

Inner housing 620 defines a chamber having an opening, when the tiregauge is fully assembled, only at port 640, and is otherwise sealed.Port 640 is adapted to engage with and open the needle valve on asuitable tire valve stem. Port 640 has a threaded boss (not shown)adapted to sealingly engage with a threaded tire valve stem. Piston 644fits within the threaded boss and is adapted to open a needle valve on avalve stem when port 640 is in sealing engagement with a suitable valvestem. Washer 646 may be provided to assist in sealing port 640 to avalve stem. PCBs 661, 662, 663 are mounted exterior to the chamber andwithin outer housing 670, and may carry thereon devices such as an RFantenna and other components such as wake up circuit components,processor and memory. A pressure sensing die 680 is positioned at an endof the chamber, and bolt 683, with washer 684, seals the correspondingopening in inner housing 620. An advantage of the embodiment of FIG. 6is that it may provide the device with a relatively significant powersource, without the need to damage any permanent components to replace abattery.

Referring now to FIG. 7, there is shown an exploded view of a tirepressure gauge 710 in accordance with an embodiment of the invention, inwhich relative internal motion of components as a result of motion ofthe device as the tire to which it is attached spins, is stored forlater use, such as by being converted to a current and coupled to abattery or capacitor. It will be appreciated that devices that obtainenergy from relative motion of internal components caused by motion ofthe device itself, are well-known. Self-winding watches store energy inthis manner, by way of example, by use of an eccentric rotor coupled toa ratchet; motion of the ratchet winds a spring. Techniques applicableto self-winding watches may be applied to a tire pressure gauge inaccordance with alternative embodiments of the invention. However, inthe embodiment of FIG. 7, an eccentric wheel 782 oscillates relative tothe housing and other components. The depicted form of eccentric wheel782 is merely exemplary, and, by way of example, other wheels or objectswith unbalanced weight and mounted to rotate, may be employed. Eccentricwheel 782 is rotatable on a mount (not shown). Bearing parts 785, 786serve to cause eccentric wheel 782 to rotate in a plane with minimalfriction. Eccentric wheel 782 has one or more permanent magnets (notshown) mounted thereon. One or more coils (not shown) may be mounted onPCB 762. A current is generated in the one or more coils when the one ormore permanent magnets move, and the current may be employed to rechargeone or more rechargeable batteries or capacitors (not shown), which maybe mounted, by way of example, on one or more of PCBs 761, 762, or aninner surface of housing 770. Alternatively, eccentric wheel 782 may becoupled to a piece of piezo film, which, when is subject to stressesand/or strains as a result of the movement of eccentric wheel 782,provides a current to one or more rechargeable batteries or capacitors.Outer housing 770 may be substantially cylindrical, and have two pieces,namely a body portion 771, open at both ends, and lid 772, which alsosupports eccentric wheel 782.

Inner housing 720 defines a chamber having an opening, when the tiregauge is fully assembled, only at port 740, and is otherwise sealed.Port 740 is adapted to engage with and open the needle valve on asuitable tire valve stem. Port 740 has a threaded boss (not shown)adapted to sealingly engage with a threaded tire valve stem. Piston 744fits within the threaded boss and is adapted to open a needle valve on avalve stem when port 740 is in sealing engagement with a suitable valvestem. Washer 746 may be provided to assist in sealing port 740 to avalve stem. PCBs 761, 762 are mounted exterior to the chamber and withinouter housing 770, and may carry thereon devices such as an RF antennaand other components such as wake up circuit components, processor,memory, battery, motion sensor (not shown) and/or capacitor. A pressuresensing die 780 is positioned at an end of the chamber, and bolt 783,with washer 784, seals the corresponding opening in inner housing 720.An advantage of the embodiment of FIG. 7 is that it may provide thedevice with an internal source of power.

Referring now to FIG. 8, an alternative embodiment of a cap is shown.Cap 870 has at least one extension that is adapted to engagesubstantially opposing sides of a valve cap. In the illustratedembodiment, a plurality of fingers 873 extend from cap 870 and areadapted to engage the sides of a valve stem when the device is engagedwith a valve stem. Fingers 873 preferably are adapted to engage sides ofa valve stem under tension. Fingers 873 serve to provide additionalstability to a tire pressure gauge in accordance with an embodiment ofthe invention. While three fingers 873 are shown, the fingers may takeany desired shape, and any form of extension that provides tension onsubstantially opposite sides of cap 870 would assist in stabilizing thedevice. It will be appreciated that one or more of fingers 873 may behollow and enclose components of a tire pressure gauge.

Referring now to FIG. 9, there is shown an alternative embodiment of apressure sensing module 980, with an additional sensor, which may eitherbe a pressure sensing die or a temperature sensor, provided. In thisembodiment, module 980 has a pressure sensing die 981 on the side facingan interior chamber, so that pressure sensing die 981 provides a signalindicative of a pressure in the chamber. On the opposite side of module980 a second pressure sensing die 982 is provided. Pressure sensing die982 may be employed to obtain a relative pressure. Temperature readingsmay also be obtained. Alternatively, a single die with multiple sensorsmay be provided. Multiple sensor dies may be provided for the purpose ofoffset compensation, as will be appreciated by those of skill in theart.

Referring now to FIG. 10, there is shown a block diagram of anembodiment of a tire pressure gauge having a pressure sensor and atemperature sensor. Processor 1010, memory 1020, RF antenna 1050, wakecircuit 1060, pressure sensor 1040, optional A/D converter 1030, andoptional motion sensor 1070 may be the same as those discussed above inconnection with FIG. 3. Temperature sensor 1041 provides an outputsignal indicative of a temperature of the air in the chamber, and thusindicative of the air temperature in the tire. Temperature sensoroutputs its signal to optional A/D converter 1031, which provides thedigitized signal to processor 1010.

Referring now to FIG. 11, a cross-sectional view of a tire pressuregauge 1100 is illustrated, according to an embodiment of the invention.Pressure gauge 1100 includes a bottom housing 1110, a top housing 1130and a battery lid or cover 1120. A battery 1150 is housed in battery lid1120. In an exemplary embodiment, battery lid 1120 includes externalthreads 1123 adapted to engage internal threads 1113 of bottom housing1110. Battery lid 1120, thus, may be relatively easily disengaged frombottom housing 1110 to replace battery 1150. An O-ring 1125 seals theinterface between battery cover 1120 and bottom housing 1110, therebyreducing the likelihood of moisture entering the interior of pressuregauge 1100. Bottom housing 1110 further includes positive batterycontact 1155 and negative battery contact 1157 for connecting battery1150 to a controller PCB 1160. Controller PCB 1160 may include aprocessor (e.g., processor 510 of FIG. 5), a wake circuit (e.g., wakecircuit 520 of FIG. 5), a memory (e.g., memory 570 of FIG. 5) and othercircuit elements. Controller PCB 1160 further includes a motion sensor1161 in the form of a motion switch dome 1163 and a motion switch ball1165, in an exemplary embodiment. It will be understood that motionsensor 1161 may include other types of motion sensors and accelerometersas are known in the art. Motion sensor 1161 may be employed to activatethe processor (e.g., processor 510 of FIG. 5) to receive an outputsignal from the pressure sensor (e.g., pressure sensor 480 of FIG. 5).

Now also referring to FIG. 12, which illustrates an exploded view ofpressure gauge 1100 of FIG. 11, a sensor PCB 1170 is in electricalcommunication with controller PCB 1160. In one configuration, sensor PCB1170 includes first and second pressure sensors 1171, 1173 and circuitelements for an RF transmitter, which elements are not described infurther detail for the sake of brevity. In an exemplary embodiment,first and second sensors 1171, 1173 may respectively be adapted to sensethe tire pressure and the atmospheric pressure, as set forth herein. Anantenna coil spring contact 1177 is in electrical communication withsensor PCB 1170 and associated RF transmitter circuit elements. A tophousing 1130 is fastened to bottom housing 1110. Top housing 1130includes a port 1133 having internal threads 1135. Port 1133 is adaptedto accommodate and to be mounted on a valve stem of a tire via internalthreads 1135. Pressure gauge 1100 further includes a pin (not shown) toopen a valve mounted in the valve stem of a tire.

Referring now to FIG. 13, there is shown a block diagram of a remotecommand or display device 1300, which may be employed with a tirepressure gauge described herein to cause a value to be displayed by, forexample, display 1350, and to store new threshold values in, forexample, memory 1320. Remote command device 1300 has a processor 1310,which may be, by way of non-limiting example, a microprocessor. Memory1320 of remote command device 1300 may be internal or external toprocessor 1310 and may take the form of one or more random-access memory(RAM), read-only memory (ROM), programmable read-only memory (PROM),erasable programmable read-only memory (EPROM), or electrically erasableprogrammable read-only memory (EEPROM) chips, by way of non-limitingexample only. An on/off input 1330 may include a user-operable on/offswitch and a circuit to provide a wake signal to processor 1310 when auser operates the on/off switch to activate device 1300. Input keys 1340are user-operable and provide inputs to processor 1310. By way ofnon-limiting example, input keys 1340 may include “up” and “down” keysfor scrolling through menus, a “select” key for selecting a displayedand highlighted or otherwise designated menu item, and a “Reset” key.Alphanumeric display 1350 may include text, numbers and/or graphicalsymbols, and may be, by way of example, an LCD display, with or withoutlighting. RF Antenna 1380 may be a radiofrequency transmitter/receiverthat can transmit and receive data, or may use another form of wirelesstransmission.

Remote command device 1300 may be a handheld device contained in ahousing convenient to hold in the hand, and having an internal source ofpower, such as an internal battery, according to an embodiment of theinvention. In another configuration, by way of non-limiting exampleonly, remote command device 1300 may be adapted to be mounted on a wall.In an exemplary configuration, remote command device 1300 is externallypowerable; by way of non-limiting example only, device 1300 may bepowered externally through an AC adaptor or an external battery such asa 12 Volt automobile battery. Such externally powerable remote command1300 is, therefore, operative, independent of the operational state ofthe vehicle whose tire pressure is being monitored. Thus, externallypowerable remote command device 1300 is configured to be powered from asource external to device 1300 as well as external to the vehicle whosetire pressure is being monitored. Non-limiting examples of externallypowerable command device 1300 include device 1300 powered through an ACpower outlet via an AC adapter, device 1300 powered through anautomotive battery not installed in a vehicle or a marine battery suchas a 12 V battery, and device 1300 powered through any power sourceother than a battery internal to device 1300 or a battery disposed inthe vehicle whose tire pressure is being monitored. Of course, display1300 may, in addition, be configured to be powered by the vehiclebattery or an internal battery, such as a back-up battery or arechargeable battery recharged via a source of AC power. In anotherembodiment, remote command device 1300 may also be configured to bepowered through a cigar lighter power receptacle of a motorcycle. Remotecommand device 1300 may also have an illumination source, such as a“white” LED, or an incandescent lamp with reflector, to provideillumination.

Referring now to FIG. 14, there is shown a remote display unit 1400 fora tire pressure measurement system, according to an embodiment of theinvention. In the illustrated embodiment, display unit 1400 includes ahousing 1410, a display 1420, and first and second user input buttons1430, 1440. In an exemplary embodiment, display 1420 may take the formof Liquid Crystal Display (LCD). Other embodiments may include othertypes of displays. Yet other embodiments may include a combination ofdifferent types of displays. By way of non-limiting example only,display 1420 may take the form of LCD as well as one or more lightemitting diodes (LEDs). In an exemplary embodiment, button 1430 is “SET”button, and button 1440 is a toggle button for “UP” and “DOWN.” It willbe appreciated that other embodiments of display unit 1400 may have morethan or fewer than two buttons. It will be appreciated that otherarrangements and functions of buttons are also contemplated to be withinthe scope of the invention. In an exemplary embodiment, display unit1400 further includes a hidden “RESET” button (not shown) at the back ofhousing 1410. In one configuration, display unit 1400 is adapted to bemounted on a wall, by way of non-limiting example. In an exemplaryembodiment, display unit 1400 may be powered by an AC adaptor.

Referring now to FIG. 15, an exploded view of the remote display unit1400 is illustrated. Housing 1410 (of FIG. 14) includes a top cover 1510and a bottom cover 1520. In one configuration, remote display unit 1400is configured to be mounted on a wall. In an exemplary embodiment, abracket or holder 1530 is secured to bottom cover 1520, therebyrendering remote display unit 1400 configured to be mounted on a wall.Bracket 1530 is adapted to be secured to a wall, for example, to mountdisplay unit 1400 to the wall. Other mechanisms, such as screw-eyes andreleasable mounts, may also be used to mount display unit 1400 to awall. Housing 1410 (of FIG. 14) houses a controller PCB 1540, a buttonPCB 1550, a backlight plate 1560, an LCD panel 1570, and a lens 1580.Controller PCB 1540 may include components such as a processor (e.g.,processor 1310 of FIG. 13), a memory (e.g., memory 1320 of FIG. 13), anRF antenna (e.g., RF antenna 1380 of FIG. 13) and associated RFtransmitting and receiving circuit elements. Button PCB 1550 is inelectrical and/or physical communication with buttons 1430, 1440 andcontroller PCB 1540. Back light plate 1560 and LCD panel 1570 are inelectrical communication with controller PCB 1540. Back light plate1560, LCD panel 1570 and lens 1580 serve to act as the display 1420 ofFIG. 14.

Referring now to FIG. 16, there is illustrated schematically a system orkit 1600 for tire pressure monitoring for a motorcycle 1610, accordingto an embodiment of the invention. In one configuration, motorcycle 1610includes a front tire 1620 and a rear tire 1630. System or kit 1600includes a first tire pressure gauge 1625 configured to be mounted onthe valve stem of front tire 1620, a second tire pressure gauge 1635configured to be mounted on the valve stem of rear tire 1630, and aremote display unit 1400. Tire pressure gauges 1625, 1635 may take theform of any one of pressure gauge 10 (of FIG. 1), pressure gauge 410 (ofFIG. 4A), pressure gauge 610 (of FIG. 6), pressure gauge 710 (of FIG.7), or pressure gauge 810 (of FIG. 8). Remote display unit 1400 has atleast one setting mode wherein a user can store preferred tire pressurethresholds for each of tires 1620, 1630 and one registering mode whereina user can associate a particular tire pressure gauge (e.g., gauge 1625)with a preferred tire (e.g., front tire 1620). Remote display unit 1400may includes components illustrated in block diagram of FIG. 13. In anexemplary embodiment, tire pressure gauges 1625, 1635 are adapted to bein one-way wireless communication with remote display unit 1400, i.e.,to output wireless signals indicative of the pressure and the batterystatus information, which wireless signals may be received by remotedisplay unit 1400. Processor 510 (of FIG. 5) may be configured todetermine the strength and/or the charge in battery 560 (of FIG. 5),either absolutely or as a percentage or ratio of total charge, and maybe configured to cause RF module 540 (of FIG. 5) to emit a wirelesssignal including data indicative of the determined battery strength orcharge, for example. In another embodiment, tire pressure gauges 1625,1635 may be adapted to be in two-way wireless communication with remotedisplay unit 1400, i.e., to receive wireless signals from remote displayunit 1400, for example, to wake or activate the processor (e.g.,processor 510 of FIG. 5).

Referring now to FIG. 17A, an exemplary layout of display 1420 isillustrated. Schematic FIG. 1710 represents motorcycle 1610 (of FIG. 16)with elements 1720, 1730 representing front tire 1620 and rear tire 1630respectively. Display 1420 is configured to display one or moregraphical indicators indicative of a tire pressure detected by pressuresensor 480 (of FIG. 5). In an exemplary configuration, the graphicalindicators take the form of graphical bars 1725, 1735. Each element1720, 1730 has an associated graphical bar 1725, 1735 respectively. Eachgraphical bar 1720, 1730 is divided into three sectors 1725 a, 1725 b,1725 c and 1735 a, 1735 b, 1735 c respectively. In the illustratedembodiment, each of three sectors 1725 a, 1725 b, 1725 c of bar 1725 andeach of three sectors 1735 a, 1735 b, 1735 c of bar 1735 is adapted toilluminate in a different color. For example, sectors 1725 a, 1735 a areadapted to illuminate in green, sectors 1725 b, 1735 b are adapted toilluminate in yellow, and sectors 1725 c, 1735 c are adapted toilluminate in red. It will be appreciated that in other embodiments,bars 1725, 1735 may be divided into more than or fewer than threesectors and that sectors 1725 a, 1725 b, 1725 c, 1735 a, 1735 b, 1735 cmay illuminate in colors other than those described above. It willfurther be appreciated that sectors 1725 a, 1725 b, 1725 c, 1735 a, 1735b, 1735 c may take the form of a LED in an embodiment of the invention.

A text field 1722 is positioned adjacent to element 1720 and is adaptedto display at least a value indicative of the tire pressure for fronttire 1620 in the illustrated embodiment. A graphical symbol 1726 isindicative of the strength of RF signal received from tire pressuregauge 1625 (of FIG. 16) associated with front tire 1620 of motorcycle1610. Similarly, a graphical symbol 1724 is indicative of the batterystatus (e.g. of battery 560 (of FIG. 5), as determined by processor 510(of FIG. 5) and communicated by RF module 540 (of FIG. 5) to remotedisplay unit 1400) of tire pressure gauge 1625 (of FIG. 16) associatedwith front tire 1620 of motorcycle 1610. Likewise, graphical symbol 1736is indicative of the strength of RF signals received from tire pressuregauge 1635 (of FIG. 16) associated with rear tire 1630 and graphicalsymbol 1734 is indicative of the battery status (e.g., of battery 560(of FIG. 5)) of tire pressure gauge 1635 (of FIG. 16) associated withrear tire 1630 of motorcycle 1610.

In the illustrated embodiment, a text field 1740 is adapted to displayvarious units of pressure. By way of non-limiting example only, textfield 1740 is adapted to display one of “PSI,” “Bar,” “kPa,” and“kg/cm²,” depending on the selection by a user. Display 1420 furtherincludes first and second text fields 1750, 1760. In the illustratedembodiment, first text field 1750 is adapted to display “Limits” whenthe user has selected a setting mode to set tire pressure limits.Similarly, second text field 1760 is adapted to display “Register” whendisplay unit 1400 is in the process of registering tire pressure gauges1625, 1635 associated with respective tires 1620, 1630 of motorcycle1610. In other embodiments, text fields 1750, 1760 may be adapted todisplay other messages for the user.

Referring now to FIG. 17B, an exemplary display 1420 is illustratedwherein tire pressure thresholds or target tire pressures have beenpre-set by the user, as will be described herein, and display unit 1400displays the values of tire pressure measurements detected by, andreceived from, tire pressure gauges 1625, 1635 (of FIG. 16) associatedwith respective tires 1620, 1630 of motorcycle 1610. Text field 1740indicates that the displayed pressure measurements are in PSI units.Text field 1722 indicates that the detected tire pressure of front tire1620 is 29.6 PSI and text field 1732 indicates that the detected tirepressure of rear tire 1630 is 49.7 PSI. In the exemplary embodiment, thepressure threshold for both tires 1620, 1630 is 30 PSI, for illustrativepurpose only. It will be appreciated that a user is free to setdifferent pressure threshold values for different tires. Graphicalsymbols 1726, 1736 indicate that both tire pressure gauges 1625, 1635(of FIG. 16) associated with respective tires 1620, 1630 are in RFcommunication with display unit 1400. Similarly, graphical symbols 1724,1734 indicate that the batteries (e.g., batteries 560 (of FIG. 5)) ofboth tire pressure gauges 1625, 1635 are at least partially charged. Inthe illustrated embodiment, sector 1725 a is illuminated (by way ofnon-limiting example only, in green) to indicate that the measuredpressure value for the respective front tire 1620 is equal to or withinacceptable range of pre-set pressure threshold. Likewise, sector 1735 cis illuminated (by way of non-limiting example only, in red) to indicatethat the detected tire pressure of tire 1630 is excessively beyond thepre-set threshold, i.e., in the instant case, tire 1630 isover-inflated.

Referring now to FIG. 18A and 18B, there is shown a block diagrammaticrepresentation of a process 1800, according to an aspect of the presentinvention, and being suitable for use with display unit 1400 (of FIG.14). In an initial step, indicated by block 1805, upon initiallypowering up of display unit 1400 (of FIG. 14), display unit 1400 entersa default initial display mode. In the default mode, processor 1310 (ofFIG. 13) accesses, such as from memory 1320 (of FIG. 13), a storeddefault target pressure value, and a stored default pressure unit, andcauses those target value and pressure unit to be displayed, asindicated by block 1810.

In response to a SET signal, as indicated by block 1812, display unit1400 (of FIG. 14) enters a pressure unit select mode, as indicated byblock 1815. In the pressure unit select mode, a pressure unit will blinkto prompt the user to select a pressure unit. For example, initially,pressure unit “PSI” may blink. In response to the user pressing the upand down button 1440 (of FIG. 14), the pressure unit that is blinkingwill change to another pressure unit. In response to a further SETsignal, the pressure unit for remote display unit 1400 (of FIG. 14),asdisplayed, will be selected and stored in memory, as indicated by blocks1817 and 1820, and remote display unit 1400 (of FIG. 14) will enter agoal setting mode, as indicated by block 1825.

In the goal setting mode, the user is prompted to enter a first targettire pressure, as indicated by block 1830. The first target tirepressure may be for front tire 1620 (of FIG. 16), for example, asrepresented by element 1720 (of FIG. 17). The prompting may take theform of causing element 1720 to blink or illuminate. A default targettire pressure is displayed in associated text field 1722, and may beincremented up and down in response to pressing of the up and downbuttons 1440 (of FIG. 14) by the user. When a desired first target tirepressure is displayed, the user may press the SET button 1430 (of FIG.14). This will generate a SET signal, indicated by block 1835, to theprocessor 1310 (of FIG. 13), which will then store, as indicated byblock 1840, the then-displayed value as the first target tire pressurein memory 1320 (of FIG. 13).

Referring now to FIG. 18B, the processor may then prompt the user toenter a second target tire pressure, as indicated by block 1845. Thesecond target tire pressure may be for rear tire 1630 (of FIG. 16). Theprompting may take the form of causing the element 1730 to blink orilluminate. A default second target tire pressure may be displayed inassociated text field 1732. The displayed second target tire pressuremay be incremented up and down in response to pressing of the up anddown button 1440 (of FIG. 14) by the user. When a desired second targettire pressure is displayed, the user may press the SET button 1430 (ofFIG. 14), as indicated by block 1847. In response, processor 1310 (ofFIG. 13) will store the then-displayed second target tire pressure inmemory 1320 (of FIG. 13), as indicated by block 1850. Remote displayunit 1400 (of FIG. 14) may then enter the remote display operating mode.

In an exemplary embodiment of system or kit 1600, two tire pressuregauges 1625, 1635 (of FIG. 16) are pre-registered with remote displayunit 1400. Thus, according to an embodiment of the invention, a tirepressure monitoring kit for a motorcycle includes two tire pressuregauges 1625, 1635 (of FIG. 16) each of which is configured to be mountedon a valve stem of a tire of the motorcycle, and an externally powerableremote display unit 1400. For example, first tire pressure gauge 1625(of FIG. 16) is labeled “F” to indicate front, thereby configured to bemounted on the front tire of a motorcycle. Likewise, second tirepressure gauge 1635 (of FIG. 16) is labeled “R” to indicate rear,thereby configured to be mounted on the rear tire of the motorcycle. Theuser mounts these two tire pressure gauges 1625, 1635 (of FIG. 16)respectively on the valve stems of front tire 1620 (of FIG. 16) and reartire 1630 (of FIG. 16) of motorcycle 1610 (of FIG. 16). Both tirepressure gauges 1625, 1635 (of FIG. 16) are adapted to in wirelesscommunication with remote display device 1400 (of FIG. 16) via firstradio frequency module 540 (of FIG. 5) of pressure gauges 1625, 1635 (ofFIG. 16) and second radio frequency module 1380 (of FIG. 13) of remotedisplay unit 1400 (of FIG. 14). In an embodiment, pressure gauges 1625,1635 (of FIG. 16) may be configured to be in one-way wirelesscommunication with display unit 1400 (of FIG. 16), i.e. pressure gauges1625, 1635 (of FIG. 16) may only transmit wireless signals, which may bereceived by remote display unit 1400 (of FIG. 16). In other embodiments,pressure gauges 1625, 1635 (of FIG. 16) may be configured to transmitwireless signals to, and receive wireless signals from, remote displayunit 1400 (of FIG. 16).

In other embodiments, the tire pressure monitoring kit may include twotire pressure gauges 1625, 1635 (of FIG. 16), each of which isconfigured to be mounted on a valve stem of a motorcycle tire, withoutbeing designated for a particular tire. In such case, the user may mountone of tire pressure gauges 1625, 1635 on a front tire of the motorcycleand the other on a rear tire of the motorcycle. A manual registrationprocess may then be used to register each of tire pressure gauges 1625,1635 with remote display unit 1400 as being associated with itsrespective motorcycle tire, as described below.

A process flow for manual registration of valve cap mounted tirepressure gauges 1625, 1635 and associated transmitters with the displayunit 1400 will be described with reference to FIGS. 14 and 19. In anexemplary embodiment, the user removes all batteries (e.g., 655 (of FIG.6)) of both tire pressure gauges 1625, 1635. The user then powers remotedisplay unit 1400 using, by way of example only, the AC adaptor or a 12volt cigar lighter power receptacle of motorcycle 1610 (of FIG. 16). Theuser causes a registration signal, as indicated by block 1905 to be sentto processor 1310 (of FIG. 13), such as by pressing a registration key,which may be recessed in any suitable location, so that it is notinadvertently pressed during normal use. In response, display unit 1400enters the registration mode, as indicated by block 1910.

Display unit 1400 prompts the user to activate a wireless transmissionfrom the valve-stem mounted tire pressure gauge (e.g., gauge 1625 ofFIG. 16) mounted on a particular tire (e.g., front tire 1620 of FIG.16), as indicated by block 1915, which transmission includes at least anidentifier indicative of tire pressure gauge identification informationin the form of. The prompting may include blinking or illuminatingelement 1720 (of FIG. 17) associated with the particular tire (e.g.,front tire 1620 of FIG. 16). The identification information may be analphanumeric sequence, which sequence is different at least for eachtire pressure gauge on a particular vehicle, and is stored in a memoryof the valve-stem mounted tire pressure gauge as associated with anidentifier associated with the particular tire. The user then installsbattery (e.g, battery 655 (of FIG. 6)) in first tire pressure gauge 1625(of FIG. 16) which causes first tire pressure gauge 1625 (of FIG. 16) toemit a wireless signal via RF antenna (e.g., RF antenna 350 of FIG. 3).This wireless signal includes an identifier for gauge 1625.

When the identification is received, as indicated by block 1920,processor 1310 (of FIG. 13) stores the identification and an associationbetween the gauge identifier and the identifier for the particular tire,as indicated by block 1925. When processor 1310 (of FIG. 13) hascompleted storing this information, processor 1310 may cause a successsignal to be displayed, as indicated by block 1930. For example, thesuccess signal may include blinking or illuminating the elementassociated with the particular tire a selected number of times in acolor different from the color of the prompting signal. For example, thesuccess signal may include blinking the associated element in greenthree times. In another configuration, the display may display apressure “0.0” in associated text field and activate the elementrepresentative of the other tire.

If both tires 1620, 1630 do not have an associated identification storedin memory, then, as indicated by block 1935, processor 1310 (of FIG. 11)may then prompt the user to cause other one of gauges 1625, 1635 to emita wireless identification signal. The user then installs batteries(e.g., battery 655 (of FIG. 6)) in respective pressure gauge 1635 (ofFIG. 16). The process is then repeated until an identification isassociated with each tire 1620, 1630 in memory 1320 (of FIG. 13), andthen the registration process ends, as indicated by block 1940.

According to an embodiment of the invention, the tire pressuremonitoring system or kit includes three tire pressure gauges configuredto be mounted on the valve stems of three wheels associated with athree-wheeled motorcycle and a display unit adapted to be in wirelesscommunication with the three pressure gauges and to display the tirepressures for three wheels associated with a motorcycle. It will beappreciated that this embodiment may be appropriately modified for amotorcycle with a spare tire or a motorcycle with a one-wheel trailerwithout departing from the scope of the invention. An exemplary partiallayout 2000 of display 1420 (of FIG. 14) is illustrated in FIG. 20.Layout 2000 includes a stick diagram 2010 representing a three-wheeledmotorcycle having three wheels 2020, 2030, 2040. Each wheel 2020, 2030,2040 has an associated textbox 2025, 2035, 2045 and an associatedgraphical bar 2022, 2032, 2042 respectively. Graphical symbols 2026,2036, 2046 are indicative of the strength of RF signals received from atire pressure gauge (e.g., gauge 10 (of FIG. 1)) associated with each ofrespective wheels 2020, 2030, 2040 of motorcycle 2010. Similarly,graphical symbols 2024, 2034, 2044 are indicative of the battery statusof the batteries (e.g., battery 860 (of FIG. 8)) of the tire pressuregauges (e.g., gauge 10 (of FIG. 1)) associated with the respectivewheels 2020, 2030, 2040 of motorcycle 2010.

According to yet another embodiment of the invention, the tire pressuremonitoring system or kit includes four tire pressure gauges configuredto be mounted on the valve stems of four wheels associated with amotorcycle and with a two-wheeled trailer, and a display unit adapted tobe in wireless communication with the four pressure gauges and todisplay the tire pressures for the two motorcycle wheels and the twotrailer wheels associated with the motorcycle. An exemplary partiallayout 2100 of display 1420 (of FIG. 14) is illustrated in FIG. 21.Layout 2100 includes a stick diagram 2110 representing a two-wheeledmotorcycle having two wheels 2130, 2140 and a stick diagram 2120representing a two-wheeled trailer having two wheels 2150, 2160. Eachwheel 2130, 2140, 2150, 2160 has an associated text field 2135, 2145,2155, 2165 and an associated graphical bar 2132, 2142, 2152, 2162respectively. Graphical symbols 2136, 2146, 2156, 2166 are indicative ofthe strength of RF signals received from a tire pressure gauge (e.g.,gauge 10 (of FIG. 1)) associated with respective wheels 2130, 2140 ofthe motorcycle and respective wheels 2150, 2160 of the trailer.Similarly, graphical symbols 2134, 2144, 2154, 2164 are indicative ofthe battery status of the batteries (e.g., battery 860 (of FIG. 8)) ofthe tire pressure gauges (e.g., gauge 10 (of FIG. 1)) associated withthe respective wheels 2130, 2140 of the motorcycle and respective wheels2150, 2160 of the trailer.

It will be understood that the processes depicted in FIGS. 18A-18B and19 may be appropriately modified for use with the systems depicted inFIGS. 19 and 20 and, therefore, are not described in detail for the sakeof brevity.

Referring now to FIG. 22, a schematic diagram of a tire pressuremonitoring system 2200 is illustrated, according to an embodiment of theinvention. System 2200 includes a valve-stem mounted tire pressure gauge410 and an externally powerable remote display unit 1300. In theillustrated embodiment, tire pressure gauge 410 includes a processor510, a periodically activating wake circuit 520, a memory 570 accessibleto processor 510, a pressure sensor 480, an RF antenna or module 540, anoptional A/D converter 530 and an optional motion sensor 580 in ahousing. Tire pressure gauge 410 is described in further detail abovewith reference to FIG. 5. Remote display unit 1400 includes a processor1310, a memory 1320 accessible to processor 1310, an RF module orantenna 1380, a display 1350, input keys 1340 and an on/off input 1330in a housing. Remote display unit 1400 is described in further detailabove with reference to FIG. 13. Tire pressure gauge 410 and remotedisplay unit 1300 are configured to be in wireless communication asdepicted by broken line 2210. In particular, RF antenna or module 540 ofpressure gauge 410 and RF antenna or module 1380 of remote display unit1300 are configured to be in wireless communication with each other. Inthe illustrated embodiment, externally powerable remote display unit1300 is powered by an AC power supply 2230 through AC adapter 2220.

Now referring to FIG. 23, a process flow for transmission of a wirelesssignal from the pressure gauge 410 (of FIG. 22) is illustrated. At block2310, processor 510 (of FIG. 22) is activated by wake circuit 520 (ofFIG. 22). At block 2320, processor 510 (of FIG. 22) receives an outputof pressure sensor 480 (of FIG. 22). At block 2330, processor 510 (ofFIG. 22) retrieves a previously stored tire pressure value from memory570 (of FIG. 22). At block 2340, processor 510 (of FIG. 22) compares thepreviously stored tire pressure value with the output of pressure sensor480 (of FIG. 22). If the difference between the output of pressuresensor 480 (of FIG. 22) and the previously stored tire pressure value isless than a predetermined value, then processor 510 (of FIG. 22) returnsto an inactive or sleep state, as indicated by block 2360. Processor 510(of FIG. 22) remains in an inactive state for a preset period of time;at the end of the preset period of time, wake circuit 520 (of FIG. 22)sends a wake signal to processor 510 (of FIG. 22). If the difference ismore than the predetermined value, then processor 510 (of FIG. 22)causes RF module or antenna 540 (of FIG. 22) to emit a wireless signalindicative of the output of pressure sensor 480 (of FIG. 22) at block2350. Processor 510 (of FIG. 22) replaces the previously stored value inmemory 570 (of FIG. 22) with the output of pressure sensor 480 (of FIG.22), as indicated at block 2370, and then sleeps for a predeterminedperiod of time, at block 2360, until activated again by wake circuit 520(of FIG. 22).

The valve cap mounted tire pressure gauges may be similar to thosedepicted in FIG. 9 of commonly owned U.S. patent application Ser. No.11/589,329, filed Oct. 27, 2006, now U.S. Pat. No. 7,667,583, whichapplication is incorporated by reference in its entirety. Those tirepressure gauges include as a power source a battery adapted to beremoved and replaced easily. In particular, such a tire pressure gaugeincludes a battery compartment having a lid which may be removed andreplaced readily, and particularly by rotating. The lid is generally asolid cylinder, and has a latch, which mates with a protrusion. Byplacing a flat object, such as a coin or screwdriver blade, into a slotprovided in the lid, the user may turn the lid sufficiently to disengagethe latch from the protrusion, and thereby remove the lid and remove andreplace the battery. An O-ring may be provided to prevent moisture fromentering the interior of battery compartment. The valve-stem mountedtire pressure gauges include an RF emitter.

It will be appreciated that each of the ports for coupling to andmounting to a valve stem of a vehicle tire may be adapted to mount on avalve stem by virtue of having interior threads which permits them to bescrewed or threaded onto a valve stem. It will be appreciated thatalternative structures may be included in the port for providing thatthe port is adapted to mount on a valve stem. The ports for coupling toand mounting on a valve stem may be adapted to couple to and mount on avalve stem with no modification to the valve stem.

Referring back to FIG. 16, the operation of the tire pressure monitoringsystem for a motorcycle according to an embodiment of the invention willnow be described. A remote display unit 1400 may be located in a garage,for example, where the motorcycle is parked. In an exemplary embodiment,the unit 1400 may be mounted. on a wall (for example, via bracket 1530of FIG. 15). In one configuration, remote unit 1400 is powered throughan AC adaptor, thereby dispensing with the need to monitor the batterystatus. First and second valve-stem mounted tire pressure gauges 1625,1635 are mounted on the valve stems of the front and rear tires 1620,1630 of motorcycle 1610 and accordingly registered with remote displayunit 1400.

The pressures of the front and the rear tires are measured by therespective pressure gauges 1625, 1635 periodically, for example, everythirty (30) seconds. It will be understood that the period betweenmeasurements may be smaller than or larger than 30 seconds. Theprocessor (e.g., processor 310 (of FIG. 3)) of pressure gauge 1625, 1635compares the recently measured pressure value with the immediately priormeasured pressure value stored in the memory (e.g., memory 570 (of FIG.5)). If the recently measured pressure value differs from theimmediately prior measured pressure value by at least a predeterminedthreshold amount, the pressure gauge processor (e.g., processor 510 (ofFIG. 5)) causes the pressure gauge RF antenna (e.g., antenna 350 of FIG.3) to emit a wireless signal indicative of the latest measured tirepressure value.

Remote display unit 1400 displays the measured tire pressuresnumerically as well as graphically, as set forth herein, as receivedfrom pressure gauges 1625, 1635. Thus, the tire pressures of themotorcycle are monitored on a continuous basis without any user input.When a user enters the garage, a simple glance at remote display unit1400 is sufficient to relay the tire pressure information for themotorcycle. Remote display unit 1400 also display the status of thebattery 560 (of FIG. 5), thereby conveying to the user if and when thebatteries (e.g., battery 560 of FIG. 5) in pressure gauges 1625, 1635need to be replaced. In one configuration, the on/off input (input 1330of FIG. 13) may be omitted, since the remote display unit iscontinuously powered through an AC adapter.

Advantages of a device and method in accordance with the inventioninclude permitting the user to determine whether a tire isunderpressurized without the need to remove a tire valve stem cap andphysically engage a tire pressure gauge with the tire valve stem cap.Some configurations of valve stem mounted tire pressure gauges, includea motion sensor in the valve stem mounted tire pressure gauge toactivate the pressure sensor. However, since a motorcycle may be usedrecreationally or otherwise intermittently used, the motorcycle may beidle and parked for prolonged periods of time without any movement. Anadvantage of the present system is that the wake circuit permitspressure measurements even in an idle or parked state of the motorcycle,i.e., independent of the operational state of the motorcycle. Thus, theinformation regarding the tire pressures of the motorcycle is alwaysavailable regardless of whether the motorcycle engine or any associatedaccessory such as electrical/electronic devices are actually activated,provided the remote display is supplied sufficient power, for example,from an AC power supply and the batteries of the tire pressure gaugesare functional. Since the motorcycle tires are susceptible to pressurelosses due to prolonged storage, such a system advantageously providesthe tire pressure information to a rider, before the rider operates orattempts to operate the motorcycle. The system provides the tirepressure information without any input from the rider as the externallypowerable remote display unit continuously displays the detected tirepressure values in a numerical as well as a graphical format. Thus, asingle glance at the remote display unit is sufficient, to inform therider regarding the need, or lack thereof, to inflate the tires beforeoperating the motorcycle, even after a prolonged period of storage. Yetanother advantage of the externally powerable display unit is that auser is spared the tasks of monitoring and/or changing the batteries inthe display unit.

A further advantage is that a device in accordance with an embodiment ofthe invention is that such devices may be installed on vehicles withminimal effort and cost associated with installation. A furtheradvantage of a device in accordance with some embodiments of theinvention is that the user may provide the recommended tire pressure ofthe user's own vehicle to the device, thereby avoiding the need to havethis pressure pre-stored when the device is manufactured. An advantageof an embodiment having both an active pressure sensor and a referencepressure sensor is that readings will be compensated for variations intemperature, for example, while the gauge remains on the valve stem.Additional advantages of embodiments of the invention will be evident tothose of skill in the art.

While the foregoing invention has been described with reference to theabove-described embodiment, various modifications and changes can bemade without departing from the spirit of the invention. For example,the number of wheels and the associated pressure gauges may be changedwithout departing from the spirit of the invention. Accordingly, allsuch modifications and changes are considered to be within the scope ofthe appended claims.

1. A tire pressure monitoring system comprising: a valve-stem mountedtire pressure gauge, said gauge comprising: a first processor; apressure sensor, in communication with said first processor, fordetecting a tire pressure; a wake circuit adapted to periodicallyactivate said first processor to receive an output of said pressuresensor, said output indicative of a tire pressure detected by saidpressure sensor; a memory, accessible to said first processor, forstoring a value indicative of a tire pressure detected by said pressuresensor; and a first radio frequency module, in communication with saidfirst processor, for emitting a wireless signal indicative of a tirepressure detected by said pressure sensor; an externally powerableremote display unit, said unit comprising: a second processor; a secondradio frequency module in communication with said second processor, saidsecond module configured to wirelessly communicate with said first radiofrequency module; and a display, in communication with said secondprocessor, for displaying at least a graphical indicator indicative ofthe tire pressure detected by said pressure sensor.
 2. The tire pressuremonitoring system of claim 1, wherein said first processor causes afirst tire pressure measurement value to be stored in said memory,responsive to a first output signal, from said pressure sensor,indicative of the first tire pressure measurement value, wherein,responsive to a second output signal, from said pressure sensor,indicative of a second tire pressure measurement value, said firstprocessor compares the second value with the first value, and wherein,if the second value differs from the first value by more than apredetermined value, said first processor causes said first radiofrequency module to emit a wireless signal indicative of the secondvalue.
 3. The tire pressure monitoring system of claim 1, said tirepressure gauge further comprises a motion sensor configured to activatesaid first processor responsive to detection of motion of said tirepressure gauge.
 4. The tire pressure monitoring system of claim 1,wherein said remote display unit is configured to be powered via an ACpower supply.
 5. The tire pressure monitoring system of claim 1, whereinsaid remote display unit is configured to be mounted on a wall.
 6. Atire pressure monitoring kit for a motorcycle, said kit comprising: afirst and a second tire pressure gauge, each of said tire pressuregauges being configured to be mounted on a valve stem of a tire of themotorcycle, each of said first and second tire pressure gaugescomprising: a first processor; a pressure sensor, in communication withsaid first processor, for detecting a tire pressure; a wake circuitconfigured to periodically activate said first processor to receive anoutput of said pressure sensor, said output indicative of a tirepressure detected by said pressure sensor; and a first radio frequencymodule in communication with said first processor, for at least emittinga wireless signal indicative of a tire pressure detected by saidpressure sensor; and a remote display unit comprising: a secondprocessor; a second radio frequency module in communication with saidsecond processor, said second module configured to wirelesslycommunicate with said first radio frequency modules of said first andsecond tire pressure gauges; a memory accessible to said secondprocessor, for storing at least a target tire pressure; and a display,in communication with said second processor, for displaying at least agraphical indicator indicative of a tire pressure detected by saidpressure sensors.
 7. The kit of claim 6, wherein each of said first andsecond tire pressure gauges comprises a memory in communication withsaid first processor and configured to store at least a value indicativeof a tire pressure detected by said pressure sensor.
 8. The kit of claim6, wherein each of said first and second tire pressure gauges isconfigured to be in wireless communication with said remote display unitindependent of the operational state of the motorcycle.
 9. The kit ofclaim 6, wherein said remote display unit is externally powerable. 10.The kit of claim 9, wherein said remote display unit is configured to bepowered either by an AC power supply or an external battery.
 11. The kitof claim 6, wherein said remote display unit is configured to display atleast a graphical symbol representative of a motorcycle.
 12. The kit ofclaim 6, wherein said remote display unit is configured to display atleast a graphical indicator representative of a tire pressure detectedby said pressure sensor.
 13. The kit of claim 6, wherein said remotedisplay unit is configured to display at least a graphical indicatorindicative of a difference between a first value indicative of a tirepressure detected by said pressure sensor and a second value indicativeof a target tire pressure and stored in said memory.
 14. The kit ofclaim 6, further comprising a third tire pressure gauge configured to bemounted on a valve stem of a tire associated with the motorcycle.
 15. Amethod of monitoring tire pressure for a motorcycle comprising the stepsof: periodically activating a processor in a valve-stem mounted tirepressure gauge to receive an output of a pressure sensor in said tirepressure gauge, said output indicative of a tire pressure detected bysaid pressure sensor; causing, by said processor, a first radiofrequency module in said tire pressure gauge to emit a wireless signal,said wireless signal indicative of a tire pressure detected by saidpressure sensor; receiving, at a second radio frequency module in anexternally powerable remote display unit, said wireless signal emittedby said first radio frequency module; and displaying, in said remotedisplay unit, a graphical indicator representative of a value of thetire pressure detected by said pressure sensor.
 16. The method of claim15, wherein the step of periodically activating said processor isindependent of the operational state of the motorcycle.
 17. The methodof claim 15, further comprising the steps of: storing a first value in amemory in said tire pressure gauge, said first value being indicative ofa tire pressure detected by said pressure sensor; and comparing, by saidprocessor, a second value indicative of a second tire pressure detectedby said pressure sensor with said first value, wherein said first radiofrequency module is caused to emit a wireless signal if said secondvalue differs from said first value by more than a predetermined value.18. The method of claim 15, further comprising the step of storing in amemory in said remote display unit an association between a firstidentifier indicative of the identity of said tire pressure gauge and asecond identifier indicative of the identity of said tire.